Spark plug socket



FIG. 1 is a front perspective view;

FIG. 2 is a rear perspective view;

FIG. 3 is a side view;

FIG. 4 is a front view; and,

FIG. 5 is a rear view.

The broken line showing of the interior of the spark plug socket is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a spark plug socket, as shown and described. 